Process of manufacturing ammonium chloride



Sept. 23, 11930 PRocsss oF MANUFACTURING Armonrum cHLoRIDE Filed June 1, 1927 Lonmmlrxou Patented' sept,.- 23,1930.'

'uNrrEn` STATES- PATENT OFFICE SHAM,` ENGLAND, A ssIGNons To IMPERIAL CHEMICAL INDUSTRIES LIMITEnjoIF LONDON, ENGLAND, A BRITIsHCoMPANY i APROCESS or MANUFACTURING AMMCNIUM CIILoEIIJE v i Application filed .Tune 1, 192'?, Serial No. 195,745, and in Great Britain June 25, I

This invention relates to improved processes of manufacturing ammonium chloride. The objectof the invention is toprovide an improved cyclic process. A further bject is to produce ammoniu; chloride of high chemicalpurity by direct combination. According to the invention, We effect an interaction between ammonia and hydrochloric acid in presence of hydrogen-in such a manner as to precipitate ammonium chloride, after which the excess of hydrogen`is employed for the synthesis of further quantities of the" initial reagents, namely ammonia or hydrochloric acid, in such manner that the Whole process can be made cyclic inasmuch as a repeated'series of operations can be performed vWithout substantial loss of hydrogen.

' We prefer to use synthetic ammonia obtained'by direct synthesis from nitrogen'and hydrogen in known manner) and We also prefer to use synthetic hydrochloric acid (obvtained by direct combinationof hydrogen with chlorine.)

"Inthe accompanying drawing-s r- Figure 1 1s an illustration inl vertical section offa suitable reaction-chamber .Figure2 -is a diagrammatic flow sheet.

chloric acid is usedwhich has been obtained in any other manner.

Ichloric acid obtained by burningchlorine in excess,v of hydrogen, e. g. the mixture may contain 30% of free hydrogen. This mixture is introduced through pipe 3 (Fig. l) into a tubular or other reaction'chamber l which may be lined with tiles 2 and the ammonia is introduced through pipe 4. Before reaching the reaction-chamber the ammonia and gaseous .mixture of hydrogen and hydrochloric acid may be rendered substantially anhydrous preferably by. low temperature cooling or by other means. The reaction chamber is provided with doorsor apertures 8 through which the precipitated ammoniu'rr" chloride can' be removed. Anoutstanding .end and is sent through a -filterd feature of ,the ammonium chloride as lpro'- -JosErH WILLIAM MOORE, or IIUNCORN', AND WILFIRID GUsrAv roLACx, or Imonduced is its extraordinary-purity and suit ability for use Without further refining where a pure substance is required.

The hydrogen leaves the tubeat Ithe other i to remove any suspended ammoniuml chloride after which it is `passed through pipes 6'and'7 to the' synthetic ammonia plant or to' the synthetic hydrochloricacid plant.` VVhen'-thel residual hydrogen is employed for ammonia synthesis,rit-is .desirable toV use a slight excess of 'ammonia over hydrochloric acid when admitting the gases into the tube and conversely when the'residual hydrogen is. to be used for 'hydrochloric acid synthesis. 1t 1s desirable to employ aslight excess Vof hydrochloric acid. The small excess of either gasmay be removed by subsequent absorption if desired and in this Way foreign sub-v stances are eliminated from the synthesis plant as far as required.

' i Eamgle 2 Yrlhe gases from a'synthetic ammonia plant 'containing hydrogen, nitrogen and ammonia are caused 'to react with pure hydrochloric But, provided hydrogen is -present. during the reaction the process of the invention can 'be emplo ed even if ammonia vorl hydro:

acid gas which may or may not contain free hydrogen)- The reaction may take place'underh" h pressure or not. The ammonium 'chlori e is obtained inthe form of a solid or of a strong solution; The residual hydrogen and nitrogen are' again employedv forV ammonia synthesis if necessary after suit ably adjusting the ratio of hydrogen to nitrogen by the addition of nitrogen or, hydrogen as required. In this modification qf our invention, the ammonia can beremoved from the'gases as ammonium chloride Without liquefaction or scrubbing with Water.

In Fig. 2, l0 is the synthetic ammonia plant, 11 a reducing valve, 1 the lreaction vessel, l15

the filter and 16 the compressor. 'Hydro chloric acidis added at-13 and make-up gases at 14.

.We declare that What We claim is 1. The cyclic process of manufacturing ammonium chloride which consists in combining. gaseous ammonia as one reagent` With gaseous hydrbchloricacid as another reagent in presence of hydrogen, removmg ammoniu'mhchloride and synthesizing one of said reagents by the use of the residual hydrogen.

5 2. 'The process of manufacturing ammonium chloride which consists in combining gaseous synthetic ammonia with gaseous syntheticl hydrochloric acid in presence .of hydrogen, removing ammonium chloride in m solid form, and utilizing' the hydrogen for synthesis of one of the initial reagents used in the process. y 8. The process of manufacturing ammonium chloride which lconsists in mixing the gases from an ammonia synthesis plant with hydrochloric acid, removing the animonium chloride so formed and passing the residual gases to the synthesis plant.

In Witness whereof, We have hereunto o signed our names this 19th day'of May, 1927.

u JOSEPH WILLIAM MOORE. i

`WILFRID GUSTAV-POLACK. 

